<?php

/**
 * Implements hook_FORM_ID_form_alter().
 *
 * Override comment form.
 */
function groups_comment_form_comment_form_alter(&$form, &$form_state) {
  global $user;

  // Display the user's picture.
  $wrapper = entity_metadata_wrapper('user', $user);
  $path = empty($user->picture) ? variable_get('user_picture_default') : $wrapper->value()->picture->uri;
  $form['user_picture'] = array(
    '#theme' => 'image_style',
    '#style_name' => '50x50_avatar',
    '#path' => $path,
    '#prefix' => '<div class="user-picture">',
    '#suffix' => '</div>',
    '#weight' => -20,
  );
  // hide subject field
  $form['subject']['#access'] = False;
  $form['author']['#access'] = False;
  $form['comment_body'][LANGUAGE_NONE][0]['#placeholder'] = t('Write a comment...');
  $form['comment_body'][LANGUAGE_NONE][0]['#resizable'] = False;
  $form['comment_body'][LANGUAGE_NONE][0]['#rows'] = 3;
  $form['comment_body'][LANGUAGE_NONE][0]['#title_display'] = 'invisible';
  // remove preview button
  unset($form['actions']['preview']);
}

/**
 * Implements hook_text_format_alter.
 *
 * Set default text format to markdown for the group/body field.
 */
function groups_comment_text_format_alter(&$element) {
  if ((isset($element['#bundle'])) && (isset($element['#field_name']))) {
    if (($element['#bundle'] == 'comment_node_post') && ($element['#field_name'] == 'comment_body')) {
      // set default value to markdown
      $element['format']['format']['#default_value'] = 'markdown';
      // hide text format filter
      $element['format']['#access'] = FALSE;
    }
  }
}